Conventionally, there have been employed disc players for reproducing information recorded on optical discs including magneto-optical discs.
FIG. 1 shows the configuration of an example of such disc players, which includes a disc rotation drive mechanism 113 for driving or rotating an optical disc 105, a reproduction mechanism 114 for reproducing information recorded on the optical disc 105, a clamp mechanism 115 for rotatably clamping the optical disc 105, a support stand 116 for supporting the disc rotation drive mechanism 113 and the reproduction mechanism 114, and a support base 117 for supporting the clamp mechanism 115 and the support stand 116.
The disc rotation drive mechanism 113 includes a disc table 131 onto which the optical disc 105 is placed for loading, and a spindle motor 132 for driving or rotating the disc table 131, as shown in FIG. 1. The disc table 131 is substantially of a cylindrical shape, and is made of metallic material having magnetism. The disc table 131 has a disc placement member 131a in the shape of a flange at the outer circumference of one cylinder end thereof, onto which the optical disc 105 is to be placed. Also, at the same cylinder end, the disc table 131 has an engagement member 133 substantially of a cylindrical shape at the inner circumference thereof, which is to be engaged with a center hole of the optical disc 105. The spindle motor 132 has a spindle shaft 134 which penetrates the disc table 131. The end of the spindle shaft 134 protrudes from the top surface of the engagement member 133 of the disc table 131.
The reproduction mechanism 114 includes an optical pickup 135 for reproducing information recorded on the optical disc 105, as shown in FIG. 1, and a shift mechanism, not shown, for causing the optical pickup 135 to shift along the radial direction of the optical disc 105. The optical pickup 135 includes an optical unit which has an objective lens for causing a laser beam to focus on the recording surface of the optical disc 105, and a lens shift unit for driving or shifting the objective lens.
The clamp mechanism 115 includes a clamp member 141 for rotatably clamping the optical disc 105, a clamp plate 142 in the shape of a disc which is to be abutted to the optical disc 105, and an operation arm 143 for causing the clamp member 141 to shift toward and away from the disc table 131, as shown in FIG. 1.
The clamp member 141 is substantially of a cylindrical shape, and includes an engagement protrusion 146 which is to be engaged with the inner circumference of the engagement member 133 of the disc table 131, and a flange 147 which is held by the operation arm 143, as shown in FIG. 1. The clamp member 141 has a magnet 148 in the shape of a crown at the outer circumference of the engagement protrusion 146, which attracts the disc placement member 131a of the disc table 131. The engagement protrusion 146 is substantially of a cylindrical shape, and is provided with a shaft hole 149 to which the end of the spindle shaft 134 is to be inserted. The flange 147 is arranged at the outer circumference of one end of the clamp member 141. The clamp plate 142 has an engagement hole 150 at its center portion, and the outer circumference of the engagement protrusion 146 of the clamp member 141 is engaged with the engagement hole 150.
The operation arm 143 has pivot shafts 151, 151 unitedly formed at substantially the halfway portion along the longitudinal direction of both opposite sides thereof, which is held by the support base 117, and allows the operation arm 143 to pivot along the directions of arrows j1 and j2 shown in FIG. 1. Also, the operation arm 143 has an operation shaft 152 at one end thereof, which is to be operated by the support stand 116 to cause the operation arm 143 to pivot along the j1 and j2 directions. The operation arm 143 has a pair of hold members 154, 154 for holding the flange 147 of the clamp member 141. The hold members 154, 154 have holders 155, 155, respectively, each substantially of a triangle shape in its cross section at the end thereof for holding the clamp member 141, as shown in FIG. 2. The holders 155, 155 are so arranged as to face the flange 147, and such that acute ends thereof are abutted to the flange 147.
The disc rotation drive mechanism 113 and the reproduction mechanism 114 are so arranged on the main surface of the support stand 116 as to face the clamp mechanism 115, respectively, as shown in FIG. 1. The support stand 116 has pivot shafts 157, 157 at one end thereof, which is held by the support base 117 and allows the support stand 116 to pivot along the directions of arrows k1 and k2 shown in FIG. 1. The support stand 116 has, at the same end, an operation member 158 in the shape of a hook for operating the operation shaft 152 of the operation arm 143. The support stand 116 is caused to pivot by a pivot mechanism, not shown, with the pivot shafts 157, 157 being its pivot center, and concurrently causes the operation arm 143 of the clamp mechanism 115 to pivot with the pivot shafts 151, 151 being its pivot center by means of the operation member 158.
The support base 117 is substantially of a U shape in its cross section, and has a rear member 167 which holds the pivot shafts 157, 157 for allowing the support stand 116 to pivot along the k1 and k2 directions, and a ceiling member 168 which holds the pivot shafts 151, 151 for allowing the operation arm 143 to pivot along the j1 and j2 directions.
When thus configured disc player reproduces information recorded on the optical disc 105, after the optical disc 105 is placed onto the disc table 131, the support stand 116 is caused to pivot along the k1 direction shown in FIG. 1, while concurrently the operation arm 143 of the clamp mechanism 115 is caused to pivot along the j1 direction shown in the same FIG. When the operation arm 143 of the clamp mechanism 115 is caused to pivot along the j1 direction, the clamp member 141 held by the holders 155, 155 is caused to shift toward the optical disc 105. When the optical disc 105 placed on the disc table 131 is abutted to the clamp member 141, the optical disc 105 is rotatably clamped between the clamp member 141 and the disc table 131.
Then, the disc rotation drive mechanism 113 of the disc player drives or rotates the optical disc 105, and the optical pickup 135 of the reproduction mechanism 114 is caused to shift along the radial direction of the optical disc 105 to reproduce information recorded thereon.
On the other hand, when the disc player releases the clamp state of the optical disc 105 clamped by the clamp member 141, the support stand 116 is caused to pivot along the k2 direction shown in FIG. 1, while concurrently the operation arm 143 of the clamp mechanism 115 is caused to pivot along the j2 direction shown in the same FIG. When the operation arm 143 of the clamp mechanism 115 is caused to pivot along the j2 direction, the clamp member 141 held by the holders 155, 155 is caused to shift away from the optical disc 105, thus the disc table 131 on which the optical disc 105 is placed and the clamp member 141 are caused to shift away from each other, which releases the clamp state of the optical disc 105.
As the optical disc 105, a CD-R (Recordable) to which information can be written once, or a CD-RW (ReWritable) whose information can be rewritten is used, which may have a backside label surface having no information onto which the user can print a desirable label.
Some kinds of printing inks of labels attached to the optical disc 105 may have adhesion. So, such a label surface of the optical disc 105 may undesirably stick to the clamp member 141, which brings about a problem that the optical disc 105 will not be released from the clamp member 141 when releasing the clamp state of the optical disc 105 clamped by the clamp member 141.
Also, Some CD (Compact Disc) rental shops may attach a management label to a CD for rent for managing CDs and customers. And, when such a management label is replaced with another one, there may remain adhesive at a portion to which the management label was attached, which also causes a label surface of a CD to have adhesion, and undesirably brings about the same problem.
As described above, with the conventional disc player, the optical disc 105 whose label surface has adhesion brings about a problem or malfunction of clamp operation.
To cope with the problem, the conventional disc player compulsorily detaches the clamp plate 142 from the optical disc 105 placed on the disc table 131.
However, when the clamp plate 142 is detached away vertically from a label surface of the optical disc 105 by the clamp mechanism 115, the clamp plate 142 have to be detached from the optical disc 105 over all the range where they are abutted to each other. So, with the conventional disc player, the clamp mechanism 115 is required to have or secure enough stiffness and drive ability, which inconveniently increases the clamp mechanism 115 and the whole apparatus in size.